Add rubygem-emoji_regex 3.0.0

Ruby Emoji Regex provides a pair of Ruby regular expressions for matching
Unicode Emoji symbols.

This is based upon the fantastic work from Mathias Bynens' emoji-regex
Javascript package. emoji-regex is cleverly assembled based upon data from the
Unicode Consortium.

The regular expressions provided herein are derived from that pacakge.

WWW: https://github.com/ticky/ruby-emoji-regex